yeah, thats what my understanding is and all the more reason to use references exclusively. cos (correct me if i'm wrong) references are the simplest way to get a hash of hashes
and (again correct me if i'm wrong) you can't pass a hash or array into a sub - it get 'flattened' into a scaler ... though if you pass a reference of a hash in there it survives perfectly intact
to me it seems like 'original 1987' perl is somewhat hampered and the the reference arrow (->) was created so that perl can do all the stuff that most modern languages do by default